1. Field of the Invention
The invention pertains to vitrectomy, and more particularly, to portable systems and methods that allow vitrectomy to be conducted in a wide variety of clinical environments.
2. Description of Related Art
Vitrectomy is the surgical removal of vitreous gel from the middle of the eye. Vitreous gel (also called vitreous humor) is a thick, colorless, gel-like fluid that fills the large space in the middle of the eye, behind the lens. Vitreous gel helps the eyeball maintain its shape.
Removal of the vitreous gel, in some cases, provides better access to the back of the eye for particular treatments. For example, vitrectomy provides access for repairing or preventing traction retinal detachment, repairing very large tears in the retina, or treating severe proliferative retinopathy. Vitrectomy may also be employed to reduce vision loss caused by severe or prolonged bleeding in the vitreous gel (vitreous hemorrhage).
Vitrectomy involves three functions: cutting, suction, and infusion. During vitrectomy, small incisions are made in the wall of the eye, through which various instruments are passed. In particular, the doctor inserts a working instrument, e.g., a vitrector, into the eye, cuts the vitreous gel, and suctions the vitreous gel out. A vitrector combines a guillotine style cutting mechanism with vacuum suction. When suction is initiated, the vitreous gel is drawn through a port in the probe tip and then severed by the cutting mechanism. In addition, saline is infused into the eyeball to keep the eyeball distended for treatment. After removing the vitreous gel, the surgeon may treat the retina with a laser (photocoagulation), cut or remove fibrous or scar tissue from the retina, flatten areas where the retina has become detached, or repair tears or holes in the retina or macula. At the end of the surgery, saline, silicone oil, or a gas is injected into the eye to replace the vitreous gel and restore normal pressure in the eye.
Vitrectomies are typically conducted in facilities dedicated to surgical procedures, such as an operating room in a hospital. Special power and gas systems are generally available in such environments. These systems are usually monitored by various computerized alarm systems. In particular, hospitals employ highly controlled power systems that provide uninterrupted electricity throughout the hospital. Furthermore, hospitals employ piped gas systems that supply pressurized oxygen, nitrous oxide, nitrogen, carbon dioxide, and/or clean outside air via pipes to operating rooms and other parts of the hospital. Because vitrectomies are typically conducted in hospital facilities, conventional vitrectomy systems are designed to rely on the special power and gas systems available in such facilities. For example, conventional vitrectomy systems that employ gas-driven vitrectors can be simply connected to a gas port readily available in a hospital operating room to receive the pressurized gas needed for driving the vitrector. Accordingly, conventional vitrectomy systems cannot be easily implemented in facilities without special systems that effectively provide unlimited power and pressurized gas.